High frequency apparatus



Jan. 26, 1937. F A KQLSTER 2,068,991

alga FREQUENCY APPARATUS Filed June 1, 1934 2 Sheets-Sheet IlE-E INVENTOR Frederick A Knlsinr ATTORNEY Jan. 26, 19537. KOLSTER 2,068,991

HIGH FREQUENCY APPARATUS Filed June 1, 1934 2 Sheets-Sheet 2 INVENTOR Freflnrick A. Knlstur BY/QW ATTORNEY Patented Jan. 26, 1937 UNITED STATES PATENT OFFICE HIGH FREQUENCY APPARATUS Application June 1, 1934, Serial No. 728,553

8 Claims.

This invention relates to vacuum tube circuits and more particularly to such circuits for very high frequency working, such as frequencies having wavelengths below five meters.

An object of the invention is to connect the tank or flywheel circuit to the electrodes of an electron relay so that such high frequency apparatus will operate more economically and efficiently and will handle greater amplitudes of power than heretofore considered possible.

The invention is particularly beneficial when applied to high frequency oscillation generators of the electron relay type.

According to one feature of the invention, where the condenser or frequency determining, tank or flywheel circuit is connected between grid and anode of the electron relay as in U. S. Patent No. 1,828,706, granted October 20, 1931, to Kolster 8: Kruesi, one plate or electrode of such condenser is directly connected by short leads to the anode of the relay while the other plate or electrode is capacitatively coupled to the grid of the electron relay. By so connecting the tank circuit to the electrodes of the electron relay a very compact structure is obtained which may be easily and economically mounted and operated.

Other objects of the invention will appear from the following description and claims.

The invention is illustrated in the accompanying drawings, wherein Fig. 1 is a side elevation, partly in section, of an electron relay with the tank circuit of the oscillation generator connected thereto according to the invention;

Fig. 2 diagrammatically illustrates the arrangement of Fig. 1 connected in circuit so as to form an oscillation generating system;

Fig. 3 shows a detail of the arangement ac cording to Fig. 1;

Fig. 4 shows one method of connecting the tank circuit to a load or work circuit; and

Fig. 5 shows a method of capacitatively connecting the tank circuit to a load or work circuit.

As shown in Fig. 1, the tank circuit ID is mounted above the electron relay H. The tank circuit II] in the form illustrated is of the type disclosed in Fig. 3 of my copending application Ser. No. 637,564, filed October 12, 1932. This tank circuit comprises a condenser element and an inductance element. The condenser element is formed by two plates or electrodes l2 and I3 maintained in spaced relation. The plate 12, annular in form, is mounted on the end of a tube or rod l5 which forms the inductance element of the tank circuit. The other plate l3, also of annular shape, is formed by the rim of a domeshaped member IE5 at the small end, M, of which it is supported on the tubular inductance element 15. The dome-shaped member with its rim may be adjusted along the length of the tube so as to vary the spacing of the condenser electrodes l2 and i3. To aid such adjustment the flange M has a screw thread engagement with the rod or tube l5. Definite engagement between these two elements also aids in supporting them and maintaining them in adjusted position. The domeshaped member i6 is provided with an opening I! for an anode current supply lead connected to the inductance element IS.

The electron relay H comprises an evacuated envelope with cathode 20, grid 2| and anode 22. These electrodes may be concentrically mounted in the envelope in any usual, well known way. The anode is provided with a plurality of leads 23 connected to terminals I8, rigidly secured to the tank circuit condenser electrode I3 and extending through openings 24 in the other condenser electrode |2. These points of connection for the anode leads to the tank circuit condenser plate are, preferably, evenly distributed in a circular manner to maintain them at a uniform distance from the grid connection to the tank circuit, thereby reducing the inductance formed by these leads. The grid or controlling electrode 2| of the electron relay II is connected electrically to terminal 26 provided on the outside of the envelope of the relay. This terminal fits into a socket 21 provided on the lower side of a plate 28. This plate 28, which may be circular in form, is spaced from the electrode [2 of the tank circuit condenser by means of a plurality of insulators l9. These insulators are secured at opposite ends to the electrode 12 and the plate 28, so that the plate is supported by the electrode. Thus, the plate 28 and the electrode I2 of the tank circuit condenser form the plates of a condenser which couples the grid of the electron relay to the tank circuit condenser electrode. Support rods 29, of which there may be several, connected to the anode 22 and sealed in the envelope of the electron relay H, indicate how the anode may be supported. The cathode may be supported by rod or wire 30 sealed into the stem 3| of the envelope, with the cathode leads also sealed in the stem. The grid 2| may be supported by the conducting wires 32 connected at their upper ends to a rod 33 sealed in the envelope and fixed to the terminal cap 26.

The tank circuit with grid coupling condenser may be readily supported by a plurality of insulators, similar to IE1, secured at one end to the condenser electrode l3 and at the other to a frame or bracket. Furthermore, the tank circuit elements are supported with the axis thereof parallel to and preferably coinciding with the axis of the concentrically disposed electrodes of the electron relay whereby, due to the symmetrical mounting, disturbing inductive effects are minimized.

The supporting and spacing insulator is, shown in Fig. 3 more clearly, is made of high frequency insulating material and is tapped at each end to receive screws by which it is fastened to the plates [2 and 28. The bent lugs 3 on the plate 28, by which the latter is connected to the insulators, allow the use of longer insulators whereby the current creepage path between plates i2 and 28 is increased.

Referring now to Fig. 2, the tank circuit is shown diagrammatically connected to the anode and grid of the electron relay. The cathode 2!] of the electron relay is supplied with heating current over the supply leads 3? from a source of heating current which may be either direct or alternating. The cathode 20 of the electron relay may be maintained at a high frequency potential above ground. This may be accomplished by means of the metallic tube 38 which surrounds the supply leads 3! and is capacitatively coupled through condensers 39 to the cathode. The metallic tube, which is a line having distributed capacity and distributed inductance, is provided with an adjustable ground connection 40 by means of which the amount of reactance in the anode-cathode circuit may be regulated. The source of anode potential for the electron relay is indicated at 45. This source is connected through choke coil 46 to the electric-a1 midpoint of the inductance element I5 of the tank circuit. To the grid 2| of the electron relay is connected, by conductor 35, a capacitatively reactance circuit 41 composed of parallel connected inductance and capacity elements 48 and 49, respectively. The capacity element 49 is variable so as to adjust the reactance of the circuit. This reactance circuit 41 is connected by conductor M to ground and is, therefore, connected between the grid and ground. The tank circuit is connected by a transmission line composed of conductors 50 and 5| to an antenna 52. The high frequency oscillation generator system according to Fig. 2 functions in the same manner as that disclosed in copending application Serial No. 728,552 of Kolster and Byrne, filed concurrently herewith.

The transmission line 59, 5|, by which the tank circuit is inductively connected to the antenna, may take the form of concentric conductors connected to the tank circuit inductance l5 in the manner shown in Fig. 4. As shown therein the cylindrical tubular inductance element it; may be internally threaded so as to be engaged by external threads on the ends of the concentric tubular conductors 5i) and 51. Thus, the connection of the transmission line to the tank circuit inductance may be easily and quickly made and adjusted. The points of connection to said inductance are such as to cause a maximum transfer of energy to the transmission line and have the line symmetrically connected to the inductance.

The transmission line 5i 5! may be capacitatively coupled to the tank circuit, as illustrated in Fig. 5, wherein to the tank circuit condenser electrodes I2 and I3 are conveniently secured plates 55 and 56 of appropriate size and shape by means of insulators 5'! and 58. The transmission line conductors 5t and 5| are directly connected to the plates 55 and 56 which are maintained in spaced relation to the condenser electrodes i2 and It and form therewith condensers serving to couple the transmission line to the tank circuit.

What is claimed is:

1. In high frequency apparatus, the combination of an electron relay having cathode, grid and anode, a tank circuit including an inductance and a condenser having two electrodes, a plurality of leads connecting one of the condenser electrodes to said anode, a metallic plate connected to said grid and supported in spaced relation to the other of said tank circuit condenser electrodes, thereby forming an auxiliary capacitance external to said tank circuit to couple said grid capacitatively to said tank circuit.

2. In high frequency apparatus, the combination of an electron relay having cathode, grid and anode, a tank circuit comprising a tubular inductance element and a condenser element composed of two spaced annular electrodes supported by said inductance element with the axis thereof substantially parallel to the axis of the electron relay, a plurality of leads connecting the anode and one of said electrodes, a metallic plate connected to said grid, and means for maintaining said plate in spaced relation to said other electrode" whereby said grid is capacitatively coupled thereto.

3. In high frequency apparatus, the combination of an electron relay having cathode, grid and anode, a tank circuit comprising a tubular inductance element and a condenser element composed of two spaced annular electrodes supported by said inductance element with the axis 4. In high frequency apparatus, the combination of an electron relay having cathode, grid and anode, a tank circuit including a condenser having two electrodes, a plurality of leads connecting one of the condenser electrodes to said anode,

a metallic plate external to said tank circuit connected to said grid and supported in spaced relation to and by the other of said tank circuit condenser electrodes, thereby to couple said grid capacitatively to said tank circuit.

5. In high frequency apparatus, the combina tion of an electron relay having cathode, grid and anode, a tank circuit comprising a tubular inductance element and a condenser element composed of two spaced annular electrodes surrounding and electrically connected to said inductance element, means connecting said tank circuit across the grid and the anode of said relay, a transmission line, and means including a plate insulatingly supported by each of said electrodes in spaced relation thereto for capacitatively coupling the transmission line to said tank circuit.

6. In high frequency apparatus, the combination of an electron relay having cathode, grid and anode, a tank circuit comp-rising a tubular inductance element and a condenser element composed of two spaced annular electrodes surrounding and electrically connected to said inductance element, means connecting said tank circuit across the grid and the anode of said relay, a transmission line composed of two concentric tubular conductors each screw threaded at one end thereof, and said tubular inductance element being internally screw threaded for connecting with the screw threaded ends of said concentric tubular conductors of said transmission line.

7. In high frequency apparatus, the combina tion of an electron relay having grid and plate electrodes and a cathode, a tank circuit including a condenser having two electrodes, a metallic plate connected to one of the relay electrodes and supported in spaced relation to one of the tank circuit condenser electrodes thereby forming an auxiliary capacitance external to said tank circuit to couple said one relay electrode capacitatively to said tank circuit, and connecting means from the other relay electrode to the other condenser electrode.

8. In high frequency apparatus, the combination of an electron relay having grid and plate electrodes and a cathode, a tank circuit including a condenser having two electrodes, a metallic plate connected to one of the relay electrodes and supported in spaced relation to and by one of the tank circuit condenser electrodes thereby forming an auxiliary capacitance external to said tank circuit to couple one said relay electrode capacitatively to said tank circuit, and connecting means for the other relay electrode to the other condenser electrode.

FREDERICK A. KOLSTER. 

